SRB causing rocket to flip upwards

[oniontrain]

Ok, here\'s the problem. I made a small SRB modeled after the Mercury deorbit motors, but whenever I fire it it flips the rocket nose up. I\'ve tried removing exhaust trails, changing the thrust vector, and everything else I can think of. Maybe somebody more familiar with this can tell me what\'s going wrong. Here\'s the part: http://dl.dropbox.com/u/21315217/mercuryretro.zip

and here\'s the config file:

// --- general parameters ---
name = MercuryBooster
module = SolidRocket
author = Oniontrain

// --- asset parameters ---
mesh = mercuryretro.DAE
scale = 1
texture = mercuryretro.png
specPower = 0.1
rimFalloff = 3
alphaCutoff = 0.5

// --- node definitions ---
// definition format is Position X, Position Y, Position Z, Up X, Up Y, Up Z
node_stack_bottom = 0.0, -.05, 0.0, 0.0, 1.0, 0.0
node_stack_top = 0.0, .00, 0.0, 0.0, 1.0, 0.0

// --- FX definitions ---

fx_exhaustFlame_yellow = 0.2, -1, 0.0,-.25,1, 0, active
fx_exhaustFlame_yellow = 0.09, -1, 0.2,.25,1,-.25, active
fx_exhaustFlame_yellow = 0.09, -1, -0.2,.25,1,.25, active



// --- Sound FX definition ---

sound_vent_medium = activate
sound_rocket_hard = active
sound_vent_soft = deactivate

// --- editor parameters ---
cost = 120
category = 0
subcategory = 0
title = Mercury Solid booster
manufacturer = Jebediah Kerman\'s Junkyard and Spaceship Parts Co.
description = A small solid booster designed to be strapped to a command pod for deorbit burns. Painted in a festive stripe pattern. 
// attachment rules: stack, srfAttach, allowStack, allowSrfAttach, allowCollision
attachRules = 1,0,1,0,1

// --- standard part parameters ---
mass = 0.05
dragModelType = default
maximum_drag = 0.3
minimum_drag = 0.2
angularDrag = 2
breakingForce = 6
breakingTorque = 6
crashTolerance = 7
maxTemp = 3600
heatDissipation = 100
stageAfter = True
stageBefore = True

// --- solid booster parameters ---

thrust = 120
dryMass = 0.05 
heatProduction = 450
fuelConsumption = 2
internalFuel = 26

fullExplosionPotential = 0.5
emptyExplosionPotential = 0.1

thrustCenter = 0,-.5, 0
Thrustvector = 0,1,0
[/code

[6677]

You sure the model file is perfectly placed in the X and Z axis (assuming a Y vertical).

The CoG is calculated by the center of the model and might be out.

[oniontrain]

Hmm, that was slightly off. Hopefully this will fix it, thanks.

-wow, that totally fixed it. Thanks a lot!

[oniontrain]

OK, I don\'t think that it\'s fixed, it still causes it to flip up, it\'s just not as pronounced.

Here\'s the part. If anybody can take a look at it it would be much appreciated.